Let's head inside. More from mark geragos at the center of so many big trials, michael jackson, scott peterson, chris brown, all hired geragos to get them out of legal trouble and the same defense lawyer is talking about all that and a whole lot more in his new book "mistrial." David wright has the story. Reporter: Mark geragos is famous for defending chris brown for beating his girl rihanna. You're not just a lawyer. They confess things to you. You're a therapist to some degree. Reporter: For michael jackson, when he was accused of molesting a child or scott peterson accused of killing his wife, it was geragos' job to defend them. Are there people you would not represent on moral grounds? I don't think that I would make moral ments. Reporter: But let's say they had captured instead of killed osama bin laden. Would you take the case? No, I don't think that i would. Reporter: Not on moral grounds, mind you. Geragos says he just feels that sort of case would belong in a military court. I don't think you should import that into the criminal justice system. Reporter: His book argues there is something wrong with the fact that america's prison population has quadrupled since 1980. Your book is the case for legal reform from, if you'll forgive me, the scumbag lawyer's point of view. We get a lot of hate mail. Reporter: From folks like nancy grace. The jury won't buy it. Nobody is buying anything from you, geragos. Reporter: Who does long to convict his clients long before his clients end up in court. My feeling is if you don't respond in the court of public opinion, then you've lost your case. I'm free. Reporter: That said he never asks whether his clients are guilty. His job is to defend them anyway. For "good morning america," david wright, abc news, los angeles.

This transcript has been automatically generated and may not be 100% accurate.